A 37-year-old transient was charged with murder on Tuesday in connection with the stabbing death of a man on a popular Irvine bike trail.

Dennis Thomas Monson Jr. is accused of stabbing Sidney Siemensma, 51, multiple times after an altercation on Jan. 19 on the San Diego Creek Trail. Authorities said the men were acquaintances.

A jogger called police around 7 a.m. to report a bleeding man on the trail, authorities said. Later that day, a patrol officer spotted Monson, already considered a suspect, on the trail and arrested him on charges of child-porn possession after searching his cellphone.

While in custody, detectives gathered additional evidence and re-arrested Monson on suspicion of murder, authorities said.

Monson pleaded not guilty on March 7 to one felony charge of possession of child porn, according to court records. It was not yet clear when he will appear in court on the murder charge.

Siemensma, a stay-at-home dad and avid bicyclist, was found near a bicycle and pronounced dead at the scene.

Contact the writer: kpuente@ocregister.com, 714-834-3773