PORTLAND (AP) – After hearing two days of testimony, a judge has denied bail to a 20-year-old man charged with murder in connection with a fatal stabbing last fall at a Congress Street apartment.

But while he found probable cause for the charge against Brandon Mills, Superior Court Justice Thomas Warren cited potential weaknesses in the prosecution’s case.

Mills is charged with killing Jarmaine Ramirez, 16, during a fight that began when Mills and his brother Antwane, 18, entered the building on Oct. 21 after children in the Ramirez family’s second-floor apartment threw water out a window onto the younger Mills.

A murder charge against Antwane Mills was dropped as part of a plea agreement in which he pleaded guilty to burglary and assault.

Warren’s ruling on probable cause came Friday after a bail hearing in which most of the witnesses against Mills were questioned by the prosecution and defense.

The judge said there could be questions about whether Mills had the state of mind to commit murder when he arrived at the apartment building, but noted that intent to murder can be formed in an instant.

Four witnesses said the Mills brothers entered Ramirez’ apartment building and then ran out a short time later. The victim’s brother and sister testified that Brandon Mills was fighting with Ramirez, who called out, “I’ve been stabbed,” and fell to the ground.

Herman Ramirez, the victim’s younger brother, testified that he saw a knife in Brandon Mills’ hand and saw him stab Jarmaine Ramirez.

The Mills brothers fled, eventually going to Boston. They turned themselves in to authorities five days later.

“It is clear that they went to that apartment in an attempt to seek retribution for the water getting thrown on Antwane,” Marchese said. “After the stabbing took place, both men took off running.”

Defense counsel Daniel Lilley argued that the state’s evidence described something less than murder.

“(Prosecutors) don’t have a murder weapon, they don’t have (evidence of) any preparation . . . These are unintentional acts,” Lilley said. “I would say that the best they could say is the crime of manslaughter has been committed.”

At the end of Friday’s hearing, Lilley asked that Mills be released on bail. He said that the Mills brothers have an uncle who was paying for their defense and would supervise them on bail at his home in Florida.

Warren said he would not rule it out, but ordered Mills held without bail for now.

The trial is expected to begin in June.