The prime suspect in the case, career criminal Youell Swinney, was linked to the murders primarily by statements from his wife plus additional circumstantial evidence.

At around 11:45 p.m. on Friday, February 22, Jimmy Hollis (25) and his girlfriend, Mary Jeanne Larey (19), parked on a secluded road just outside Texarkana, Texas, after having seen a movie together.

[7] The lovers' lane was approximately 300 feet (91 m) from the last row of city homes, where present-day Central Mall is located.

[7] Around ten minutes later, a man wearing a white cloth mask–which resembled a pillowcase with eyeholes cut out–appeared at Hollis' driver-side door and shone a flashlight in the window.

[9] Larey later told investigators that the noise was so loud she had initially thought Hollis had been shot, when in fact she had heard his skull fracturing.

[9] Thinking the assailant wanted to rob them, Larey showed him Hollis' wallet to prove he had no money, after which she was struck with a blunt object.

[14] Hollis alternately claimed the attacker was a tanned white man, and around thirty years old, but conceded he could not distinguish his features as he had been blinded by a flashlight.

[20] At around 1:30 a.m. on Sunday, April 14, Paul Martin (17) picked up Betty Jo Booker (15) from a musical performance at the VFW Club at West Fourth and Oak Street in Texarkana.

[32] The fifth murder occurred on Friday, May 3, sometime before 9 p.m., when Virgil Starks (37) and his wife Katie (36) were in their home on a 500-acre (200 ha) farm off Highway 67 East, almost 10 miles (16 km) northeast of Texarkana.

Taylor complied and, along with other members of the Prater family, took Katie to Michael Meagher Hospital (now Miller County Health Unit).

Four days later, Davis talked with Katie again, and she discounted a circulating rumor that Virgil had heard a car outside their home several nights in a row and feared being killed.

Notable investigators included: We want every man and woman in these two counties to recall the dates of these murders and [anyone who] was missing or out of the pocket during those nights.

[16] Larey returned to Texarkana after the Griffin-Moore murders in hopes of helping to link the cases and identify the killer, but the Texas Rangers questioned her story and insisted that she knew who her attacker was.

[50] The unofficial theory for a motive amongst the majority of officers was that of "sex mania", as large amounts of money in the home were not taken, nor was Katie's purse.

[34] By March 30, police had posted a $500 reward ($8,035 in 2024) in an effort to gain any new information on the case, but this produced over 100 false leads with no fruitful clues or suspects.

Booker had been a popular high-school junior, a sorority member, an officer of her high school band, a winner of scholastic, literary and musical prizes, and a former Little Miss Texarkana.

There was constant media coverage of the increased police activity[55] and the Texarkana Gazette stated on May 5 that the killer might strike again at any moment, at any place, and at anyone.

Additional items of which sales increased included window sash locks, screen door hooks, night latches, and other protective devices.

When calling on an address, law enforcement officers would turn on their sirens, stand in their headlights, and announce themselves to keep from being shot by a nervous homeowner.

Presley declared that innocent people were being accused of being the Phantom and asked residents to show more consideration for their fellow citizens.

In the April 16 edition of the Texarkana Daily News, a heading read "Phantom Killer Eludes Officers as Investigation of Slayings Pressed".

The modus operandi established for the killer was that he attacked young couples in empty or private areas just outside city limits using a .32 caliber gun.

Gonzaullas stated that he and his officers were dealing with a "shrewd criminal who had left no stone unturned to conceal his identity and activities," and that the murderer's efforts were both clever and baffling.

"[45] Dr. Anthony Lapalla, a psychologist at the Federal Correctional Institution in Texarkana, believed at the time that the killer was planning to continue to make unexpected attacks such as that of Virgil Starks on the outskirts of town.

[64] According to Lapalla's theories, the killer was not afraid of the police activity, but was aware of the increased difficulty of attacking people on vacant roads and so he had shifted his target to a farmhouse.

Her story changed in some details across several interviews, and police believed she was withholding information due to fear of Swinney or of incriminating herself.

James Freeman, a friend of Tennison, provided an alibi for the night of the Starks murder, stating that they had been playing cards that evening when they heard the news of the attack.

[67] Ralph Baumann, a 21-year-old ex-Army Air Force (AAF) machine-gunner, claimed to have awoken from a fugue state of several weeks on the day of the Starks murder, with his rifle missing.

[77] Sammie is a pseudonym given to a longtime Texarkana resident with a good reputation and no criminal record whom the police were reluctant to name as a suspect.

[79] On May 7, at approximately 6 a.m., the body of Earl Cliff McSpadden was found on the Kansas City Southern Railway tracks 16 miles (26 km) north of Texarkana, near Ogden.