Michael Maria Penttilä (born Jukka Torsten Lindholm, July 1965, Oulu, Finland) is a Finnish serial killer.

[2] Penttilä killed his mother, 48-year-old barmaid Laina Lahja Orvokki Lindholm, in their Oulu apartment on 26 August 1985.

He said that he was angered by the fact that his mother had not been able to release him from the youth facility that he was sentenced to in 1984 and that she had been dating a new man and preferred to live with him rather than Penttilä's biological father.

However, the Rovaniemi Appellate Court later held that Laina Lindholm's death was not intentional and, instead, an assault or negligent homicide, which reduced his sentence to 7 years imprisonment.

[7] According to him, he had explicitly proposed sex to the women and was playing around the neck and did not realize that the woman had died due to choking.

[7] According to psychiatric reports, Penttilä admired the primordial, violent manhood of his teenage years – despite starting to wear dresses and women's underwear while in prison.

[13] On 11 June 2010, the Oulu District Court sentenced Penttilä to six years imprisonment for three counts of attempted manslaughter and numerous assaults.

[12] In April 2011, the Rovaniemi Appellate Court considered Penttilä to have committed only three aggravated assaults, lowering the sentence to 4 years and 5 months.

At the same time, the Appellate Court ruled that the prerequisites for ordering Penttilä to serve his entire sentence in jail did not exist.

[14] On 2 March 2012, the Oulu District Court condemned Penttilä to 4 years and 4 months for aggravated rape, gross ill-treatment, and false imprisonment.

The rape and false imprisonment had taken place on 21–22 August 2009 at a hotel in Oulu, and the assault at a business in May 2009 in his apartment in Myllyoja.

[20] In April 2017, the police ordered for him to be arrested again for an alleged aggravated crime and the preparation of a criminal offense, but the Helsinki District Court released him after the investigation.

[21] On 7 July 2017, the Helsinki District Court dismissed the charge of aggravated criminal offense and ordered him to be released.

In May 2018, the Appellate Court reversed the decision, sentencing Penttilä was to 2 years and 6 months imprisonment and to pay the victim compensation of 4,000 euros.