Pat O'Brien (born May 17, 1965) is an American musician best known as the former lead guitarist for death metal band Cannibal Corpse.

Later, when he started to practice more he received his first electric guitar, a Gibson SG copy (due to his adoration of AC/DC guitarist Angus Young).

[4] His father also bought him a 1974 Gibson Flying V.[5] His influences include AC/DC, Black Sabbath, Deep Purple, Mercyful Fate and Metallica.

[citation needed] O'Brien started playing in a series of bands, sometimes as a touring musician and sometimes as a full-time member.

Between 1990 and 1992 he played in the Cincinnati-based death/thrash metal band Ceremony alongside Steve Tucker, Greg Reed and Shannon Purdon.

They released a demo in 1992 entitled Ceremony, and an EP called The Days before the Death that did not come out before 2000 and for which O'Brien did the mastering with Mark Prator.

He also toured with the band and took part in a video shoot for the song "What Tomorrow Knows" from Nevermore's eponymous debut album.

[9] Following his departure from Nevermore, O'Brien went through a transitional period where he briefly joined Monstrosity as a touring member but remained somewhat inactive for the rest of the time.

[11][12] He has been featured on every Cannibal Corpse album since Gallery of Suicide up until Red Before Black when he officially parted ways with the band.

Holt himself had been filling in for the now deceased Slayer guitarist Jeff Hanneman since February 26, 2011, subsequently joining the band.

It was basically non-stop learning and playing guitar, working through the parts with Gary Holt, came in, they had a week of shows.

In 2008 O'Brien played guitar on the song "Race Against Disaster" on Jeff Loomis's debut solo album Zero Order Phase.

In the documentary DVD Centuries of Torment: The First 20 Years bassist Alex Webster stated that "Some of his rhythm parts are as difficult as a solo might be in another band."

Drummer Paul Mazurkiewicz commended his contribution to the band's music, stating "He really is a vital part of the Cannibal [Corpse] sound.

"[citation needed] According to Cannibal Corpse vocalist George Fisher, "[O'Brien] definitely brings a more technical side, as far as playing goes.

[24] On December 10, 2018, O'Brien was arrested in Tampa for burglary of a house in the 4700 block of Windflower Circle near the Northdale Golf and Country and for assault on a responding deputy.

After one occupant told him to leave, O'Brien pushed a woman to the ground, left the house and hid in the property's backyard until police arrived.

[25][26] At O'Brien's court appearance on the morning of December 11, he wore an anti-suicide vest with his wrists and ankles chained together.

O'Brien could face up to 30 years in prison just on the charge of aggravated assault on a law enforcement officer with a deadly weapon.

[27] Flamethrowers, numerous weapons and ammunition that had caught fire and exploded were recovered inside O'Brien's home.

Another neighbor was terrified by the incident, but was thankful that the fire crew came in time to put the flames out before spreading to other homes.

Other materials found were two flamethrowers, thousands of rounds of ammunition that were stored in boxes, several other weapons with their parts and three skulls.

[32][33] On March 16, 2021, O'Brien was sentenced to 150 hours of community service, $23,793.45 restitution, a 5-year probation with alcohol and drug evaluation and treatment, and time served.

[36] Cannibal Corpse vocalist George "Corpsegrinder" Fisher spoke out and said that he was shocked to hear about O'Brien's arrest and that the fans have expressed their support for him.