A Ramsey County grand jury found that there wasn't enough evidence to charge a Hennepin County deputy and a Brooklyn Center police officer in the 2014 fatal shooting of a man who killed his companion.

Officers killed Johnathon Dean Mar, 18, of Kennewick, Wash., on Dec. 17 after he fatally shot Matthew Paul Maffei, 23, in the head at a rest stop off Interstate 94 in Maple Grove.

A Minnesota Bureau of Criminal Apprehension (BCA) investigation showed that after Maffei was killed, Mar led police on an 18-mile chase that reached speeds of up to 115 miles per hour.

Mar's sport-utility vehicle crashed in Shoreview, where he reportedly emerged from the vehicle, stabbed himself repeatedly with a knife, ignored orders to stop and then charged officers with the knife, according to the BCA.

The officers involved were Hennepin County Sheriff's Deputy Matthew Hagen and Brooklyn Center Police Officer Alan Salvosa.

A news release from the Ramsey County attorney's office said that a grand jury on Wednesday returned a "no bill" decision in Mar's shooting death, meaning the officers would not be criminally charged. At least 12 members of the randomly selected 23-person grand jury had to agree for charges to be filed.

It was unclear why Mar and Maffei were in Minnesota and what led to their encounter. They were listed as living in Washington state.

CHAO XIONG